January 22, 2019 — Each year wild salmon return to the streams in which they were born to spawn and die. Salmon fishery managers must ensure that adequate numbers of fish return each year to spawn and produce offspring for future harvest. It is expensive and labor intensive to count returning salmon, especially in remote streams.
Researchers at the University of Alaska Southeast, Auke Bay Laboratories, Oregon State University, the UK and China have found that salmon DNA collected in water samples from Auke Creek can be used to infer the number of salmon passing upstream to spawn. Two of the authors on the published paper who contributed to the research are former UAS Biology students now in graduate school, Josh Russell and Donovan Bell. Russell is currently enrolled in the UAF College of Fisheries and Ocean Sciences program, and Bell is in the biology graduate program at the University of Montana.
This form of DNA, termed “environmental DNA” or “eDNA”, can be collected from water samples. Water samples are then filtered and probed using molecular genetic techniques to quantify the amount of DNA belonging to each salmon species, providing insights into the number of salmon upstream.